Posterior lumbar plate

ABSTRACT

The present invention relates to stable fixation of spine segments, allowing for fusion in, e.g., skeletally mature patients. More particularly, the invention relates to a bone fixation device that can be affixed to vertebrae of a spine to provide reduction (or enlargement) capabilities and allow for fixation in the treatment of various conditions, including, e.g., spondyloslisthesis, degenerative disc disease, fracture, dislocation, spinal tumor, failed previous fusion, and the like, in the spine. The invention also relates to a method for delivering and implanting the bone fixation device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. Ser. No.15/705,308, filed Sep. 15, 2017 (published as U.S. Pat. Pub. No.2018-0000520), which is a continuation application of U.S. Ser. No.13/657,310, filed Oct. 22, 2012, now U.S. Pat. No. 9,788,863, all ofwhich are hereby incorporated by reference in their entireties for allpurposes.

FIELD OF THE INVENTION

The present invention relates to stable fixation of spine segments,allowing for fusion in, e.g., skeletally mature patients. Moreparticularly, the invention relates to a bone fixation device that canbe affixed to vertebrae of a spine to provide reduction (or enlargement)capabilities and allow for fixation in the treatment of variousconditions, including, e.g., spondyloslisthesis, degenerative discdisease, fracture, dislocation, spinal tumor, failed previous fusion,and the like, in the spine. The invention also relates to a method fordelivering and implanting the bone fixation plating device.

BACKGROUND OF THE INVENTION

Bones and bony structures are susceptible to a variety of weaknessesthat can affect their ability to provide support and structure.Weaknesses in bony structures can have many causes, includingdegenerative diseases (e.g., degenerative disc diseases), tumors,fractures, dislocations and failed previous fusions. Some of theseweaknesses can cause further conditions such as spondylolisthesiswherein bony structures slip out of their proper position.

In some cases of spinal surgery, it is known to use bone fixationplating devices (e.g., bone plate systems and rod and screw systems) toimprove the mechanical stability of the spinal column and to promote theproper healing of injured, damaged or diseased spinal structures.Typically, corrective surgery can entail the removal of damaged ordiseased tissue, a decompression of one or more neural elements,followed by the insertion of an interbody implant or bone graft for thepurposes of a fusion or disc arthroplasty. In cases where spinal fusionis the desired surgical outcome, the surgery can often includeimplanting a bone plate or rod and screw system in order to immobilizeadjacent vertebral bones to expedite osteogenesis across the vertebralsegments. Accordingly, there is a need to improve on bone fixationplating devices.

SUMMARY OF THE INVENTION

The present invention includes a bone fixation plating device and amethod for delivering and implanting the bone fixation plating device ina patient. The bone fixation plating device can be affixed to vertebraeof a spine of the patient to facilitate bony fusion and stabilization ofthe spine. The method includes delivering the bony fixation device to atreatment area of the spine, and affixing the device to vertebrae of thespine to, e.g., facilitate bony fusion and stabilization of the spine.

In some embodiments, a bone fixation plating device is provided fortherapeutic treatment of a patient, the device comprising: a platehaving a locking device receiving hole and a carriage receiving slot,wherein the locking device receiving hole and the carriage receivingslot are adjacent to one another and the locking device receiving holeis configured to receive and pass there-through a portion of a firstscrew; and a carriage comprising an intermediate portion that isconfigured to fit in the carriage receiving slot, the carriagecomprising a hole to receive and pass there-through a portion of asecond screw.

In some embodiments, the carriage can comprise an upper flange and alower flange. The carriage can comprise a two piece assembly thatincludes an upper carriage portion and a lower carriage portion. In someembodiments, the carriage can be a single piece structure. One of theupper flange and the lower flange can comprise an indentation that isconfigured to engage a guide in the carriage receiving slot. One of theupper flange and the lower flange can comprise a reverse bevel.

The device can further comprise a further carriage that is configured tofit in the carriage receiving slot together with said carriage, saidfurther carriage comprising a hole to receive and pass there-through aportion of a screw, wherein said carriage and said further carriage aremovable in the carriage receiving slot along a longitudinal axis of theplate.

The device can further comprise a screw having a post. The screw cancomprise a first thread and a second thread, wherein one of the firstand second threads comprises a fine thread. The other of the first andsecond threads can comprise a coarse thread. A proximal end of the screwcan comprise an open-ended guide wire capture slot. The threaded shaftof each of the two bone screws can be tapered at the distal end.

The device can further comprise a locking device. The locking device cancomprise a cutout. The locking device receiving hole of the plate cancomprise a rib that is configured to lockably engage the locking device.The locking device can comprises a ball shape or a tulip shape.

According to a further aspect of the invention, a bone fixation platingdevice is provided for therapeutic treatment of a patient, the devicecomprising: a plate having a locking device receiving hole and acarriage receiving slot, wherein the locking device receiving hole andthe carriage receiving slot are adjacent to one another and the lockingdevice receiving hole is configured to receive and pass there-through aportion of a first screw; a carriage comprising an intermediate portionthat is configured to fit in the carriage receiving slot, the carriagecomprising a hole to receive and pass there-through a portion of asecond screw; and a locking device that is configured to fasten to oneof said first and second screws and secure the plate to the first andsecond screws. The carriage can comprise a two piece assembly thatincludes an upper carriage portion and a lower carriage portion, or asingle piece structure, wherein the carriage is movable in the carriagereceiving slot along a longitudinal axis of the plate. One of the upperflange and the lower flange can comprise an indentation that isconfigured to engage a guide in the carriage receiving slot.

According to a further aspect of the invention, a method is provided forimplanting a bone fixation plating device, the method comprising:positioning a plate having a locking device receiving hole and acarriage receiving slot that includes a carriage proximate to aplurality of screws that have been implanted in bony structures;mounting the plate and carriage on to respective portions of theplurality of screws; securing the plate and carriage to the plurality ofscrews with an equal number of locking devices. The method can furthercomprise adjusting the location of the carriage with respect to thelocking device receiving hole based on the spacing between the pluralityof screws. The method can further comprise selecting a plate length andcurvature based on the spacing of the screws and the anatomical needs ofthe patient. The method can further comprise contouring, twisting,and/or bending the plate based on the anatomical needs of the patient.

Additional features, advantages, and embodiments of the invention can beset forth or apparent from consideration of the following attacheddetailed description and drawings. Moreover, it is to be understood thatboth the foregoing summary of the invention and the following attacheddetailed description are exemplary and intended to provide furtherexplanation without limiting the scope of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings, in which:

FIGS. 1A and 1B show different views of a bone fixation plating devicethat is constructed according to an embodiment of the invention;

FIGS. 2A and 2B show different partially exploded views of the bonefixation plating device of FIGS. 1A and 1B;

FIG. 3 shows a side cut view of the bone fixation plating device of FIG.2A;

FIG. 4 shows a side cut view of a portion of the bone fixation platingdevice of FIG. 2A;

FIG. 5 shows an example of a single-level bone fixation plate that canbe include in the bone fixation plating device of FIGS. 1A and 1B;

FIG. 6 shows an example of a multi-level bone fixation plate that can beincluded in the bone fixation plating device of FIGS. 1A and 1B;

FIGS. 7A and 7B depict examples of the bone screw that can be used in abone fixation plating device;

FIGS. 8A and 8B depict examples of a carriage that can be included inthe bone fixation plating device of FIG. 1A; and

FIG. 9 shows another embodiment of a bone fixation plating deviceaccording to some embodiments.

FIG. 10 shows another embodiment of a bone fixation plating deviceaccording to some embodiments.

The present invention is further described in the detailed descriptionthat follows.

DETAILED DESCRIPTION OF THE INVENTION

The aspects of the present invention and the various features andadvantageous details thereof are explained more fully with reference tothe non-limiting aspects and examples that are described and/orillustrated in the accompanying drawings and detailed in the followingdescription. It should be noted that the features illustrated in thedrawings are not necessarily drawn to scale, and features of one aspectcan be employed with other aspects as the skilled artisan wouldrecognize, even if not explicitly stated herein. Descriptions ofwell-known components and processing techniques can be omitted so as tonot unnecessarily obscure the aspects of the present invention. Theexamples used herein are intended merely to facilitate an understandingof ways in which the present invention can be practiced and to furtherenable those of skill in the art to practice the aspects of the presentinvention. Accordingly, the examples and aspects herein should not beconstrued as limiting the scope of the present invention, which isdefined solely by the appended claims and applicable law. Moreover, itis noted that like reference numerals represent similar parts throughoutthe several views of the drawings.

The terms “a,” “an,” and “the,” as used herein, are defined to mean “oneor more,” unless expressly specified otherwise. The terms “including,”“having,” “comprising,” and variations thereof, as used herein, aredefined to mean “including, but not limited to,” unless expresslyspecified otherwise.

FIGS. 1A and 1B show different views of a bone fixation plating (orposterior lumbar implant) device 100 that is constructed according to anembodiment of the invention. The bone fixation plating device 100comprises a bone fixation plate 10, a pair of posted bone screws 20(identified individually as 20 a and 20 b), and a pair of locking balls30 (identified individually as 30 a and 30 b). In some embodiments, bonescrew 20 b can be received in a carriage 40 that can slide along alength of the device 100 until a desired distance of separation betweenthe posted screws 20 a and 20 b is achieved. Once a desired distance ofseparation has been achieved, the carriage 40 can be compressed andlocked in place along the length of the plate 10. In addition, in someembodiments, the bone fixation plating device 100 is configured to allowthe posted bone screws 20 a and 20 b to rotate and/or pivot polyaxiallywith regard to the bone fixation plate 10. Accordingly, the device 100not only accommodates selective positioning of the screws 20 a and 20 brelative to one another, but also desirable polyaxial adjustment.

In FIG. 1A, the bone fixation plating device 100 is shown in anassembled (or substantially assembled) configuration, wherein thelongitudinal axes C-C of the pair of posted bone screws 20 a and 20 bare aligned substantially parallel to each other and substantiallyperpendicular to a plane of the bone fixation plate 10.

In FIG. 1B, the bone fixation plating device 100 is shown in anassembled (or substantially assembled) configuration, wherein thelongitudinal axes C-C of the pair of posted bone screws 20 a and 20 bare not parallel to each other, but instead, the longitudinal axis ofone of the posted bone screws 20 b is offset with respect to thelongitudinal axis of the other posted bone screw 20 a. Further, thelongitudinal axis of one of the posted bone screws 20 a is positionedsubstantially perpendicular to the plane of the bone fixation plate 10,and the longitudinal axis of the other posted bone screw 20 b ispositioned at an angle significantly less (or greater) than 90° (e.g.,about 65°) with respect to the plane of the bone fixation plate 10. Asseen in FIG. 1B, each of the posted bone screws 20 can advantageously bemoved polyaxially in all directions at an angle of between, e.g., about0° and about 80°, or between about 0° and about 25° with respect to anaxis normal (or perpendicular) to the plane of the bone fixation plate10. In some embodiments, the range of movement can be greater or lessthan about 0° to about 25°. Positioning of the bone screw 20 a or 20 bat an angle relative to an axis normal (or perpendicular) to the planeof the bone fixation plate 10 allows the plate 10 to accommodate formovements in the vertebrae and/or for compression of the bone graftsthat are placed between vertebrae. In addition, by providing the bonescrews 20 a and 20 b with polyaxial adjustability, this advantageouslyallows the plate to cooperate with a variety of different anatomies.

Further, as shown in FIGS. 1A and 1B, the device 100 allows for therelative positioning of the posted bone screws 20 a and 20 b to bemodified. The device 100 provides a carriage 40 for at least one of thebone screws 20 b, which allows the screw 20 b to be adjusted along alength of the plate 10. In some embodiments, the other screw 20 a, canbe in a relatively fixed position along a length of the plate 10. Asshown in FIG. 1B, the carriage 40 can include an upper flange 42 and alower flange 46 that can ride along a length of the plate 10, such thatthe plate 10 serves as a track for the carriage 40. In some embodiments,as shown in FIG. 1B, the flanges 42 and 46 of the carriage 40 can extendalong top and bottom surfaces of the plate 10. In alternativeembodiments, the flanges 42 and 46 of the carriage 40 can extend withina recess formed in sidewalls of the plate 10. Once the bone screw 20 bis placed in a desired position relative to the bone screw 20 a, thecarriage 40 can be compressed and secured onto the plate 10 (e.g., viadownward application of the compression ball 30 b along the top threadsof the bone screw 20 b, as discussed in more detail below), therebypreventing or restricting movement of the carriage 40 along the plate10.

FIGS. 2A and 2B show different partially exploded views of the bonefixation plating device 100. In these views, the compression balls 30 aand 30 b have not yet been secured to the bone screws 20 a and 20 b. Asshown in the figures, each of the bone screws 20 a and 20 b includes atop threaded section (251 a, 251 b) and a bottom threaded section (252a, 252 b), The top threaded sections 251 a, 251 b of the screws passthrough the plate 10 and accommodate the compression balls 30 a, 30 b,which are internally threaded, while the bottom threaded sections 252 a,252 b are insertable into a vertebral body, such as the pedicle.

With respect to the first bone screw 20 a, which is in a relativelyfixed position along the length of the plate 10, the bone screw 20 a canbe polyaxially adjustable relative to the plate 10 prior to downwardlysecuring the compression ball 30 a thereon. In operation, as thecompression ball 30 a travels down the top threaded section 251 a of thebone screw 20 a, this pulls the bone screw 20 a upwards, such that a topof a post section 27 a contacts an underside of the plate 10. As shownin FIG. 2A, the post 27 a of the screw 20 a comprises a widest sectionof the screw, and is configured to abut against an extension portion 12formed on the plate 10. As the compression ball 30 a is downwardlythreaded on the screw 20 a, the bottom of the compression ball 30 acompresses inwardly (e.g., via one or more cut-outs 37) into acompression fit with the plate 10, thereby locking the polyaxial motionof the screw 20 a relative to the plate 10.

With respect to the second bone screw 20 b, which is in a variableposition along the length of the plate 10, the bone screw 20 b can bepolyaxially adjustable relative to plate 10 prior to downwardly securingthe compression ball 30 a thereon. In addition, the position of the bonescrew 20 b relative to bone screw 20 a can be modified, as the carriage40 is moved along the length of the track. In operation, as thecompression ball 30 b travels down the top threaded section 251 b of thebone screw 20 b, this pulls the bone screw 20 b upwards, such that a topof a post section 27 b contacts an underside of the plate 10. As shownin FIG. 2A, the post 27 b of the screw 20 b comprises a widest sectionof the screw, and is configured to abut against the bottom of thecarriage 40. As the compression ball 30 b is downwardly threaded on thescrew 20 b, the bottom of the compression ball 30 b compresses inwardly(e.g., via one or more cut-outs 37) into a compression fit with thecarriage 40 and plate 10. As the compression ball 30 b is downwardlythreaded, the post 27 b of the screw is pulled upwards to abut and pushagainst the bottom flange 46 of the carriage 40, while the top of thecompression ball 30 b pulls down on the top flange 42 of the carriage40, thereby compressing the carriage 40 against the plate 10. Thus, thedownward threading of the compression ball 30 b on the screw 20 badvantageously locks the polyaxial motion of the screw 20 b relative tothe plate 10, and compresses the carriage 40 to secure the relativeposition of the screw 20 b relative to screw 20 a.

FIGS. 3 and 4 show side cut views of the bone fixation plating device100. In particular, FIG. 3 shows a side cut view of the bone fixationplating device 100 cut along the longitudinal axis of the bone fixationplate 10 and along an axis perpendicular to the longitudinal axes of theposted bone screws 20; and, FIG. 4 shows a side cut view of the bonefixation plate 10 and a locking ball 30 cut along the longitudinal axisof the bone fixation plate 10. As seen in FIG. 4 , the locking ball 30,which is an example of a locking device that can be used in the bonefixation plating device 100, comprises an aperture (or opening) 33 andan internal threading 35 that is constructed to receive a portion of thescrew 20 and mate with and securely fasten to a corresponding topthreaded section 251 (shown in FIG. 7A) of the screw 20. The lockingball 30 can include one or more cut-outs 37 (e.g., shown in FIG. 2A)that are configured to allow a portion of the body of the locking ball30 to be compressed inward (e.g., in the direction of the aperture 33),so as to firmly secure and lock the locking ball 30 to a portion ofscrew 20. The locking ball 30 can further include a ratcheting recess38, which can be configured to receive, e.g., a hexagonal tool such as ahex drive, wrench, or other known tool to rotate the locking ball 30,securing it to the screw 20. The locking ball 30 can include, e.g., apear-shape, a spherical shape, or any other shape that allows thelocking ball 30 and screw 20 to pivot and/or rotate with respect to thebone fixation plate 10.

FIG. 5 shows an example of the bone fixation plate 10 and the carriage40 that can be included in the bone fixation plating device 100. Asshown from this view, the carriage 40 comprises a monolithic memberassembled to the plate 10. In other embodiments, the carriage 40 can beformed of two or more members that are rotatably coupled, press-fittedor otherwise secured to one another along the plate 10. As shown in FIG.5 , the carriage 40 occupies only a certain amount of space within theplate 10. Areas adjacent to the carriage 40 can be used to insert otherdevices, such as spacers, through the plate 10 and into a desiredanatomical location. Accordingly, in some embodiments, the fixationplating device 100 can be used with other devices (e.g., spacers) aspart of a broader surgical system (e.g., for fusion).

FIG. 6 shows an example of a bone fixation plate 101 and a plurality(e.g., two) carriages 40 that can be included in the bone fixationplating device 100. In this embodiment, three screws—one in a relativelyfixed position, and two in variable positions along the length of theplate—can be accommodated. The bone fixation plate 101 can besubstantially the same as, or similar to the bone fixation plate 10,except that the slot 14 can be lengthened in a longitudinal axis A-Adirection of the bone fixation plate to accommodate a plurality ofcarriages 40.

Referring to FIG. 5 , the bone fixation plate 10 can include, e.g., asingle-level pre-lordosed plate that can be provided with an integratedcarriage 40. The bone fixation plate 10 can include a locking devicereceiving hole 12 and a carriage receiving slot 14, in which a portionof a screw 20 (e.g., shown in FIG. 1A) can pass through and be used tofasten the bone fixation plate 10 to, e.g., the vertebrae of a spine.The carriage receiving slot 14 can include an inner perimeter that formsa pair of carriage guides 141, 142, and a carriage stop 143. The pair ofcarriage guides 141, 142 can be substantially parallel to each otheralong the longitudinal axis A-A. The carriage guides 141, 142 serve toguide and support the carriage(s) 40, allowing the carriage 40 to bemoved along the longitudinal axis A-A of the bone fixation plate 10. Thecarriage stop 143 can function to prevent the carriage 40 from, e.g.,falling from the bone fixation plate 10. The bone fixation plate 10 canbe secured to, e.g., two vertebrae in order to maintain the vertebraeintegrally with respect to one another in a desired orientation and at adesired spacing from one another. The locking device receiving hole 12and the carriage receiving slot 14 are adjacent to one another along thelongitudinal axis A-A of the bone fixation plate 10. The bone fixationplate 10 can be planar and can have length and width dimensions thatsignificantly exceed its thickness dimensions. The bone fixation plate10, however, can have shapes other than planar, without departing fromthe scope or spirit of the invention.

The bone fixation plate 10 has an anterior surface 16 and a posteriorsurface 18. The length of the bone fixation plate 10 along thelongitudinal axis A-A is generally greater than its width along itstransverse axis B-B. Furthermore, the bone fixation plate 10 can becurved in a longitudinal plane that is parallel to the anterior surface16 and that includes the longitudinal axis A-A. The bone fixation plate10 can be curved in a transverse plane that is perpendicular to theanterior surface 16 and that includes the transverse axis B-B. The bonefixation plate 10 can be pre-lordosed or can be curved during surgicalimplantation.

The direction of the curvature in both the longitudinal and transverseplanes can be substantially the same (or different), such that theposterior surface 18 of the bone fixation plate 10 can be concave andthe anterior surface 16 can be convex. The radius of the curvature inthe longitudinal plane A-A can be selected to match the desired lordosisof the section of the vertebral column to which the bone fixation plate10 can be affixed. In addition, the radius of curvature in thetransverse plane can be selected to conform to the transverse curvatureof the anterior surfaces of the vertebrae. The radius of the curvaturein the longitudinal plane A-A can, therefore, be different from theradius of curvature in the transverse plane and the curvatures do notnecessarily form simple arc shapes.

While the bone fixation plate 10 can have a generally rectangular shapewith rounded corners and edges, other shapes can be utilized. The bonefixation plate 10 can be made of, or include any material, such as,e.g., a metal, an alloy, a synthetic material (e.g., carbon fiber), orany combination thereof, that would allow the plate 10 to maintain itsstructural integrity while allowing for a desired amount of resiliency.The material used can be, or can include a bio-compatible material. Thematerial is capable of withstanding the conditions of a body over adesired period of time. The bone fixation plate 10 can be formed from amaterial that minimizes interference with magnetic resonance imagingtechniques for post-operative evaluations. The bone fixation plate 10can be made from, e.g., titanium, cobalt chrome, stainless steel orother alloys or materials that are suitable for surgical implantation.

The locking device receiving hole 12 extends through the entirethickness of plate 10 and is sized to receive a locking device (e.g.,the locking ball 30 shown in FIG. 4 , or the locking device shown inFIG. 9 ) that is capable of retaining the bone screw (e.g., shown inFIGS. 7A-7B) in the bony structure (e.g., vertebrae) (not shown) inwhich it is inserted and prevent the screw from backing out of bonefixation plate 10 after the bone fixation plating device 100 isimplanted in a patient. In some embodiments, the portion of plate 10that defines the locking device receiving hole 12 can comprise ribbingconfigured to mate with, e.g., cutouts provided in the locking device(shown in FIG. 8C).

The bone fixation plate 10 includes the carriage receiving slot 14 whichaccommodates a carriage 40 (e.g., shown in FIG. 5 or FIGS. 8A-8C). Thecarriage receiving slot 14 includes the carriage guides 141, 142, andcarriage stop 143, and extends through the entire thickness of plate 10and has a length (along the longitudinal axis A-A) that is sized to belarger than a carriage 40. Typically, the length of the carriagereceiving slot 14 is large enough to integrate at least one carriage 40with space remaining on one or both sides of the carriage 40. The spaceremaining on either or both sides of the carriage 40 can advantageouslyprovide one or more windows in the plate 10 through which a surgeon canaccess the bony anatomy beneath the posterior lumbar implant device 100.In some embodiments, additional devices, such as spacers, can beinserted through these windows, such that the plate device 10 andspacers can be part of a broader fusion system. The width of thecarriage receiving slot 14 (i.e., the distance between the guides 141,142, along the transverse axis B-B) is sized to engage an outsidesurface of an intermediate portion of a carriage so that the carriage 40is securely retained in the carriage receiving slot 14.

FIG. 6 shows another example of a bone fixation plate 101 that can beincluded in the bone fixation plating device 100 (e.g., shown in FIG.1A). The bone fixation plate 101 includes a multi-level plate. In thebone fixation plate 101, the length of a carriage receiving slot 140(along the longitudinal axis A-A) is sized to be larger than two or morecarriages 40 such that two or more carriages can be integrated intoplate 10. The length of the carriage receiving slot 140 is large enoughto integrate at least two carriages 40 with space remaining between eachof the two carriage assemblies and/or space remaining on one side of atleast one of the two carriages. The space remaining between each of thetwo carriages and/or space remaining on one side of at least one of thetwo carriages provides one or more windows in the plate 101 throughwhich a surgeon can access the bony anatomy beneath the posterior lumbarimplant.

FIG. 7A shows an enlarged view of the bone screw 20, which can beincluded in the bone fixation plating device 100 (e.g., shown in FIG.1A). The bone screw 20 comprises a proximal end 21, a distal end 23 anda threaded shaft 25 extending distally from the proximal end 21 along alongitudinal axis C-C. The threaded shaft 25 can include two moredifferent types of threading, including, first threading of a topthreaded section 251 and a second threading of a bottom threaded section252. In some embodiments, the first threading of the top threadedsection 251 can be a fine threading that is configured to engage andsecurely fasten to the screw 20 to a locking device (e.g., the lockingball 30 shown in FIG. 1A). The second threading of the bottom threadedsection 252 can be a coarse threading that is configured to engage andsecurely fasten the screw 20 to, e.g., a bone. In some embodiments, thepitch of the threads of the top threaded section 251 differs from thepitch of the threads of the bottom threaded section 252. The topthreaded section 251 and bottom threaded section 251, 252 can havedifferent or substantially the same diameters. The first and/or secondthreads of the different threaded sections 251, 252 can have varyingdiameters.

In some embodiments, the proximal end 21 of the bone screw 20 can beshaped to mate with a tool adapted to rotate the screw 20 (e.g., torotate the screw 20 in order to implant the screw into a bonystructure). For instance, the proximal end 21 of the bone screw 20 cancomprise a hexagonal recess that receives a hexagonal tool such as a hexdrive, or a slot or cross that receives a screwdriver. The bone screw 20can further comprise a post 27 that is positioned between the distal end23 and the proximal end 21. The post 27 extends away from the threadedshaft 25 in a plane that is substantially perpendicular to thelongitudinal axis C-C.

The bone screw 20 is comprised of, e.g., a metal, an alloy, a syntheticmaterial, or any combination thereof. The bone screw 20 is typicallymade of a material that allows the screw to maintain its structuralintegrity while allowing for a desired amount of resiliency. Thematerial used is usually bio-compatible and is capable of withstandingthe conditions of a body over a desired period of time.

As seen in FIG. 7A, the threaded shaft 25 of the bone screw 20 can betapered at the distal end 23 and an outer perimeter of the post 27 cancomprise notches 253 that can be engaged by a tool (not shown) to rotateand drive the screw 20 into bony tissue (not shown).

FIG. 7B shows another example of a bone screw 200 that can be includedin the bone fixation plating device. The proximal end 210 of the screw200 can comprise an open-ended guide wire capture slot to accommodate aguide wire 29. Utilization of a guide wire 29 in each of the bone screws200 can enable a surgeon to position the locking device receiving hole12 and carriage 40 of a plate 10 over the bone screws 200 more easilythan in cases where the guide wire 29 is not employed.

FIG. 8A shows an example of the carriage 40 that can be included in thebone fixation plating device. In some embodiments, the carriage 40 canbe monolithic. In other embodiments, the carriage 40 can be formed ofmultiple pieces (e.g., rotatably coupled together). The carriage 40comprises an upper flange 42 and a lower flange 46 connected by (orintegrally formed with) an intermediate portion (guide) 44 along an axisD-D. The intermediate portion 44 comprises an outside surface 44 a andan inside surface 44 b. The inside surface 44 b defines a locking devicereceiving hole and the outside surface 44 a is configured to mate withthe carriage guides 141, 142 in the plate 10 (e.g., shown in FIG. 5 ).In some embodiments, the inside surface 44 b can comprise ribbingconfigured to engage with the outside surface of the intermediateportion of the locking device (e.g., locking ball 30 shown in FIG. 1A)to securely hold the locking device in the locking device receiving holeonce the locking device is inserted therein. The inside surface 44 b caninclude, e.g., a flared surface portion that is constructed to allow thelocking device to pivot and/or rotate about the axis D-D.Advantageously, the carriage 40 is provided with a series of surfacecuts 49, which increase the compressibility of the carriage 40.

The carriage 40 can be made of the same material as (or a differentmaterial from) the plate 10. The carriage 40 can be made of a materialthat comprises, e.g., a metal, an alloy, a synthetic material, or anycombination thereof. The material can be bio-compatible and capable ofwithstanding the conditions of a body over a desired period of time.Carriage 40 can be formed from a material that minimizes interferencewith magnetic resonance imaging techniques for post-operativeevaluations. The carriage 40 can be made of a material that comprises,e.g., titanium, cobalt chrome, stainless steel or other alloys ormaterials that are suitable for surgical implantation.

FIG. 8B shows the undersides of the upper flange 42 and lower flange 46of the carriage 40 of FIG. 8A in further detail. In particular, theunderside of the upper flange 42 can comprise an indentation 42 a alongone (or two) of the edges of the flange 42 that reduces the thickness ofthe upper flange 42 so that it can contact and engage the anteriorsurface 16 of the plate 10 (e.g., the guide 141, 142 shown in FIG. 5 ).More specifically, the indentation 42 a allows the upper flange 42 toengage and overlap with the anterior surface 16 of the portion of theplate 10 that defines the guides 141, 142 of the carriage receiving slot14, thereby preventing the upper flange 42 from twisting or turningwhile securely, with the assistance of the lower flange 46, holding thecarriage 40 in the plate 10. The lower flange 46 can also include asimilar indentation (not shown) to the indentation 42 a.

Also seen in FIG. 8B is the underside of the lower flange 46 of thecarriage assembly 40 shown in FIG. 8A. As seen in FIG. 8B, the undersideof the lower flange 46 of the carriage 40 can comprise a reverse bevel46 a. When the proximal end 21 of the bone screw 20 is inserted into andthrough the locking device receiving hole of the carriage 40 (or plate10), and then into the aperture 33 (e.g., shown in FIG. 4 ) in thelocking device, the locking device can be turned to mate the lockingdevice 30 to the screw 20 and pivotally fasten the locking device andscrew 20 to the carriage 40 (or plate 10). The reverse bevel 46 a canengages with the post 27 in the bone screw 20 to provide a pivot stopfor the screw 20 and locking device 30, thereby preventing the screw 20from pivoting beyond a predetermined threshold (e.g., about 25°) withrespect to the normal to the plane of the plate 10.

The locking device receiving hole 12 of plate 10 and the locking devicereceiving hole of the carriage 40 (e.g., shown in FIG. 4 ) allow thebone screw 20 to be inserted in through and locked at an angle of (insome embodiments), e.g., between about 0° and 25° away from normal axisto the plane of plate 10 and of the carriage 40 (e.g., at an angle ofabout 0° and 25° away from an axis that is perpendicular to the plane ofplate 10 and at an angle of, e.g., about 0° and 25° away from the axisD-D of the carriage 40, respectively).

FIG. 8B illustrates further details of the outside surface 44 a of theintermediate portion 44 of the carriage 40. As seen, the outside surface44 a of the intermediate portion 44 can comprise a helical groove 48that aids the carriage 40 in translating along the longitudinal axis A-Aof the carriage receiving slot 14. The helical groove 48 can enable thecarriage 40 to lock into a particular position within the carriagereceiving slot 14.

FIG. 9 illustrates another example of a bone fixation plate 1000, acarriage 400, and a plurality of locking devices 300. In someembodiments, the locking devices 300 are of similar construction to thecompression balls described above.

The bone fixation plate 1000 includes a carriage receiving slot 1400,which comprises a pair of substantially parallel guides 1410, 1420. Thecarriage receiving slot 1400 can further include a carriage stop 1430.The walls of the guides 1410, 1420 and the carriage stop 1430 can be,e.g., annular, substantially flat, or have any other surface shape thatcan engage and secure the carriage 400 to the bone fixation plate 1000.

The carriage 400 comprises an upper carriage portion 410 and a lowercarriage portion 420. The upper carriage 410 can include a plurality ofcutouts 1412. The bottom carriage 420 can be configured such that itsecurely mates with the upper carriage 410 via a rotational fit, a pressfit, a compression fit or other type of fit. In some embodiments, thecutouts 1412 of the upper carriage portion 410 can allow the lower edgeof the upper carriage portion 410 to expand and securely engage thelower carriage portion 420, thereby forming a single-piece carriage thatcan ride along the rails of the plate 1000.

The carriage 400 can be moved along the longitudinal axis A-A of thecarriage receiving slot 1400 of the plate 1000. When the carriage 400translates along the longitudinal axis A-A of the carriage receivingslot 1400, the relative position of the bone screws 20 a and 20 bassociated with the plate 1000 is changed and dynamic compression (orexpansion) is provided between multiple bony structures secured to theplate 1000. The carriage 400 can be configured to allow for polyaxialpivoting and/or rotation of a screw received within the carriage until alocking device 300 is inserted therein and fastened to the carriage 400,As described above, a screw 20 b (e.g., a pedicle screw) can extendthrough the carriage 400 and the plate 1400. The locking device 300 canbe downwardly threaded onto the screw 20 b, thereby compressing theupper carriage 410 and lower carriage 420 in a like manner as discussedabove. Once the locking device 300 is downwardly threaded, this helpslock the polyaxial angle of the screw 20 b relative to the plate 10, aswell as the relative distance between the screw 20 b and another screw20 a received within the plate.

The locking device 300 comprises a main body 310 having an upper portion310 a, a lower portion 310 b, a top 310 c and a bottom 310 d. The top310 c of the locking device 300 can be shaped to mate with a tooladapted to rotate the locking device 300 (e.g., to rotate the lockingdevice 300 within the locking device receiving hole of the carriage 400,or plate 1000, such that the locking device 300 mates with the carriage400 or plate 1000). For instance, the top 310 c of the locking device300 can comprise a hexagonal recess (as shown in FIG. 8C) that receivesa hexagonal tool such as a hex drive, or a slot or cross that receives ascrewdriver. Alternatively, the top 310 c of the locking device 300 canbe configured with a protruding engagement surface that can engage witha tool or device having a corresponding recess. The upper portion 310 a,together with the top 310 c, defines an aperture dimensioned to receivea bone screw 20 that transcends through the lower portion 310 b of thelocking device.

The lower portion 310 b of the locking device 300 comprises an outsidesurface 330 and an inside surface (not shown). The outside surface 330is shaped and configured to mate with the locking device receiving holeof the carriage 400 and/or the plate 1000. The lower portion 310 b cancomprise cutouts 335 that are capable of compression to enable lockablemating with ribbing in the locking device receiving hole of carriageassembly 400 and/or plate 1000. The locking device 300 comprises anaperture (not shown) that is dimensioned to receive a bone screw 20. Theinside surface (not shown) of locking device 300 can comprise threadingthat is capable of mating with the threads of the threaded shaft 25 of abone screw 20.

In some embodiments, the aperture (not shown) in the locking device 300can be a keyhole-shaped passage (not shown) that includes a centralcylindrical portion (not shown) that receives the proximal end 21 of abone screw 20. The cutouts 335 permit expansion and reduction in thesize of the central cylindrical portion. When the size of the centralcylindrical portion is reduced, the proximal end 21 of the bone screw 20is secured within the locking device 300.

The outside surface of the upper portion 310 a can have a shape of,e.g., a bowl, a cup, a cone, or the like, wherein a top part of theupper portion 310 a can have a diameter that is the same or differentfrom the diameter of the bottom part of the upper portion 310 a. Theoutside surface 330 of the lower portion 310 b of the locking device 300can have an inverted shape to that of the upper portion 310 a, such thatthe upper portion 310 a and lower portion 310 b can be mirror images ofone another when viewed relative to a longitudinal axis E-E.Alternatively, the upper portion 310 a and lower portion 310 b can beshaped differently.

FIG. 10 shows an example of a bone fixation plating device 1001 thatcomprises a locking device 50 including a tulip shaped attachment.Advantageously, the tulip shaped attachment can receive other implants(e.g., rods) to assist in future revisions to the system. In someembodiments, the tulip shaped attachment is detachable from the rest ofthe locking device.

The locking device 50 comprises a main body 51 having an upper portion51 a and a lower portion 51 b. The upper portion 51 a of the lockingdevice 50 is defined by an outside wall 53 which has a proximal end 53 aand a distal end 53 b. The outside wall 53 can comprise two open-endedslots 53 c and 53 d positioned opposite of one another relative to alongitudinal axis I-I. The two open-ended slots 53 c and 53 d can extenddistally from the proximal end 53 a to the distal end 53 b of theoutside wall 53 and can be sized to receive a rod.

The distal end 53 b of the outside wall 53 can comprise ascrew-receiving aperture (not shown) that transcends the distal end 53 bof the upper portion 51 a to reach the lower portion 51 b. Thescrew-receiving aperture (not shown) can be large enough to receive theproximal end 21 of a bone screw 20 inserted through the lower portion 51b of the locking device 50, or another fastening device to be used witha rod.

The lower portion 51 b can be shaped e.g., as an inverted bowl or cup,wherein the upper part of the lower portion 51 b can have a diameterthat is smaller than the diameter of the lower part of the lowerportion. The lower portion 51 b of the locking device comprises anoutside surface 55 and an inside surface (not shown). The outsidesurface 55 can be shaped and configured to mate with the locking devicereceiving hole of the carriage 40 and/or of plate 10. Typically, theoutside surface 55 comprises threads that are capable of threadablymating with ribbing in the locking device receiving hole of a carriage4000 and/or a plate 1010.

The inside surface (not shown) defines an aperture (not shown) that isdimensioned to receive a bone screw 20 according to the disclosure. Theaperture (not shown) can be a keyhole-shaped passage (not shown) thatincludes a central cylindrical portion (not shown) that receives a bonescrew 20 and one or more cutouts (not shown) which permit expansion andreduction in the size of the central cylindrical portion. When the sizeof the central cylindrical portion is reduced, the bone screw 20 issecured within the tulip-shaped locking device 50.

Referring to FIG. 1A, the bone fixation plate device 100 can bedelivered to, and implanted into a patient. A method of implanting thebone fixation plate device 100 can include drilling one or more holesinto a location of one or more bony structures (e.g., vertebrae) in thepatient. A first screw 20 a and plate 10 having a carriage 40 attachedthereon can be provided, wherein the first screw 20 a is polyaxiallyadjustable relative to the plate 10. The first screw 20 a extendsthrough a first slot in the plate 10 and can be inserted into the holein the vertebrae. A compression ball 30 a can be downwardly threadedonto the top of the first screw 20 a to thereby secure the angle of thescrew 20 a relative to the plate 10. A second screw 20 b can also beprovided and inserted into a hole formed in the vertebrae. The secondscrew 20 b can extend through the carriage 40 of the plate 10, which canslide along a length of the plate 10. Like the first screw 20 a, thesecond screw 20 b is polyaxially adjustable relative to the plate 10. Acompression ball 30 b can be downwardly threaded on to the top of thesecond screw 20 b to thereby secure the angle of the screw 20 b relativeto the plate 10. The compression ball 30 b also helps to compress thecarriage 40, thereby securing the relative position of the second screw20 b relative to the first screw 20 a.

In other embodiments, both screws 20 a and 20 b are inserted intopredetermined holes formed in the vertebrae. Once the screws 20 areproperly secured and in position, a bone fixation plate 10 having anappropriate length and curvature can be selected. In some embodiments,the bone fixation plate 10 can be preselected based on the desiredspacing between the screws 20, so as to provide the proper spacingbetween the screw receiving opening 12 in the plate 10 and the screwreceiving opening in the carriage 40. The plate 10 can be pre-curved forboth lordotic and extra-lordotic conditions. Additional contouring canbe possible utilizing an instrument (not shown) to bend or twist theplate 10 based on anatomical needs of the particular patient.

Once the plurality of bone screws 20 are securely and properly affixedto (or in) the one or more bony structures, and the proper bone fixationplate 10 has been selected (and/or reconfigured to meet anatomicalneeds), the bone fixation plate 10 can be positioned near and theopenings in the plate 10. One opening of the plate 10 can align with thefirst screw 20 a, while a second opening of the plate 10 including acarriage 40 can be aligned with the proximal end 21 of a second screws20 b. The carriage 40 in the bone fixation plate 10 can be moved in thebone fixation plate 10 along the longitudinal axis of the bone fixationplate 10 to provide appropriate spacing, if necessary. After properalignment of the bone fixation plate 10 to the bone screws 20 a and 20b, the bone fixation plate 10 (including the carriage 40) can be movedtoward and mounted on the bone screws 20, such that the locking devicereceiving hole 12 of the posterior surface 18 of bone positioning plate10 mounts over and on to the proximal end 21 of the first bone screw 20a and the locking device receiving hole of the carriage 40 mounts overand on to the proximal end 21 of the second bone screw 20 b. As notedearlier, guide wires 29 can be provided (e.g., shown in FIG. 7B) tofacilitate easier alignment of the screws 20 to the openings in theplate 10 and carriage 40.

After the bone fixation plate 10 is mounted on the first and second bonescrews 20, one or more locking devices 30 can be threaded onto theproximal end 21 of the first bone screw 20 a and then onto the proximalend 21 of the second bone screw 20 b. This can be accomplished by takinga first locking device 30 a and fastening it to the first bone screw 20a, and then reducing it into the plate 10 (or carriage 40) by turningthe locking device 30 a until it securely engages and locks to the plate10 (or carriage 40). Similarly, a second locking device 30 b can befastened to the remaining screw 20 b and then reduced into the carriage40 (or plate 10) until it securely engages and locks to the carriage 40(or plate 10). In some embodiments, the spacing between the carriage 40and opening 12 in the plate 10 can be adjusted after one of the screws20 has been secured and locked to the carriage 40 (or plate 10), butbefore the remaining screw 20 has been locked to the plate 10 (orcarriage 40).

The first and second bone screws 20 can be screwed into one or more bonystructures at an angle that is (in some embodiments), e.g., betweenabout 0° and 25° away from the axis normal to the plane of the plate 10.Because the screws 20 are not constrained to being inserted at an anglethat is perfectly perpendicular to the longitudinal axis A-A of theplate 10, the screws 20 can be closely spaced without interfering withone another. In some embodiments, the first and second bone screws 20can be inserted into, e.g., adjacent vertebrae.

As noted earlier, the proximal end 21 of the first and second bonescrews 20 can comprise an open-ended guide wire capture slot toaccommodate the guide wire 29. Guide wires 29 can be inserted into theopen-ended guide wire capture slots of the screws 20 after the distalend 23 of each of the screws 20 are screwed into the one or more bonystructures.

One or more than one carriage 40 can be mated with the carriagereceiving slot 14 of the plate 10. When only one carriage 40 is matedwith the carriage receiving slot 14 of the plate 10, the plate 10 is asingle-level plate. When more than one carriage 40 is mated with thecarriage receiving slot 14 of the plate 10, the plate 10 is amulti-level plate.

While the invention has been described in terms of exemplaryembodiments, those skilled in the art will recognize that the inventioncan be practiced with modifications in the spirit and scope of theappended claims. These examples given above are merely illustrative andare not meant to be an exhaustive list of all possible designs,embodiments, applications or modifications of the invention.

What is claimed is:
 1. A method of implanting a bone fixation platingdevice, the method comprising: providing a bone fixation plating device,wherein the bone fixation plating device includes: a plate comprising afirst slot and a second slot; a carriage configured to be disposed inthe plate and adapted to longitudinally slide in the second slot, thecarriage further having a through lumen and a concave inner surface inthe through lumen; a first bone screw extendable through the first slot;and a second bone screw extendable though the second slot, wherein thefirst bone screw is substantially fixed along a full length of theplate, while the second bone screw is capable of translation along aselected length of the plate, implanting the first bone screw into avertebral body; implanting the second bone screw into an adjacentvertebral body; positioning the plate such that the first bone screwextends through the first slot and the second bone screw extends throughthe second slot; securing the plate to the first bone screw with a firstlocking device and securing the plate to the second bone screw with asecond locking device having an exterior convex surface adapted topolyaxially couple to the concave inner surface of the carriage throughlumen.
 2. The method of claim 1, wherein the carriage is not disposed inthe first slot.
 3. The method of claim 2, wherein the first bone screwcomprises a first top threaded section and the second bone screwcomprises a second top threaded section.
 4. The method of claim 3, thefirst locking device including a first locking ball associated with thefirst bone screw and the second locking device including a secondlocking ball associated with the second bone screw.
 5. The method ofclaim 4, wherein rotation of the first locking ball and the secondlocking ball secures the orientation of the first bone screw and thesecond bone screw relative to the plate.
 6. The method of claim 5,wherein the first locking ball and second locking ball are internallythreaded.
 7. The method of claim 1, wherein the carriage is disposed inthe second slot, wherein the carriage includes an upper flange and alower flange.
 8. The method of claim 7, the first locking device havinga first locking ball associated with the first bone screw and the secondlocking device having a second locking ball associated with the secondbone screw, wherein rotation of the second locking ball causes the plateto be clamped between the upper flange and the lower flange.
 9. Themethod of claim 1, the first locking device including a first lockingball threaded over the first bone screw.
 10. A method of implanting abone fixation plating device, the method comprising: providing a bonefixation plating device, wherein the bone fixation plating deviceincludes: a plate comprising a first slot and a second slot, wherein thesecond slot is at least twice the length of the first slot; a carriageconfigured to be slidably coupled to and longitudinally slide in thesecond slot, the carriage further having a through lumen and a concaveinner surface in the through lumen; a first bone screw extendablethrough the first slot; and a second bone screw extendable though thethrough lumen of the carriage disposed in the second slot, wherein thefirst bone screw is substantially fixed along a full length of theplate, while the second bone screw is capable of translation along aselected length of the plate by the carriage, implanting the first bonescrew into a vertebral body; implanting the second bone screw into anadjacent vertebral body; positioning the plate such that the first bonescrew extends through the first slot and the second bone screw extendsthrough the second slot and the carriage; securing the plate the firstbone screw with a first locking device and securing the plate to thesecond bone screw with a second locking device having an exterior convexsurface adapted to polyaxially couple to the concave inner surface ofthe carriage through lumen.
 11. The method of claim 10, wherein thefirst bone screw comprises a first top threaded section and the secondbone screw comprises a second top threaded section.
 12. The method ofclaim 11, the first locking device including a first locking ballassociated with the first bone screw and the second locking deviceincluding a second locking ball associated with the second bone screw.13. The method of claim 12, wherein rotation of the first locking balland the second locking ball secures the orientation of the first bonescrew and the second bone screw relative to the plate.
 14. The method ofclaim 13, wherein the first locking ball and second locking ball areinternally threaded.
 15. The method of claim 10, wherein a carriage isdisposed in the second slot, wherein the carriage comprises an upperflange and a lower flange.
 16. The method of claim 15, the first lockingdevice having a first locking ball associated with the first bone screwand the second locking device having a second locking ball associatedwith the second bone screw, wherein rotation of the second locking ballcauses the plate to be clamped between the upper flange and the lowerflange.
 17. The method of claim 10, the first locking device including afirst locking ball threaded over the first bone screw.